package namespace::clean;
+# ABSTRACT: Keep imports and functions out of your namespace
-=head1 NAME
+use warnings;
+use strict;
-namespace::clean - Keep imports and functions out of your namespace
+use vars qw( $STORAGE_VAR );
+use Package::Stash;
-=cut
+our $VERSION = '0.20';
-use warnings;
-use strict;
+$STORAGE_VAR = '__NAMESPACE_CLEAN_STORAGE';
-use vars qw( $VERSION $STORAGE_VAR );
-use Symbol qw( qualify_to_ref );
-use Filter::EOF;
+BEGIN {
+ if (eval {
+ require B::Hooks::EndOfScope;
+ B::Hooks::EndOfScope->VERSION('0.07'); # when changing also change in Makefile.PL
+ 1
+ } ) {
+ B::Hooks::EndOfScope->import('on_scope_end');
+ }
+ else {
+ eval <<'PP' or die $@;
-=head1 VERSION
+ {
+ package namespace::clean::_ScopeGuard;
-0.04
+ sub arm { bless [ $_[1] ] }
-=cut
+ sub DESTROY { $_[0]->[0]->() }
+ }
-$VERSION = 0.04;
-$STORAGE_VAR = '__NAMESPACE_CLEAN_STORAGE';
+ use Tie::Hash ();
+
+ sub on_scope_end (&) {
+ $^H |= 0x020000;
+
+ if( my $stack = tied( %^H ) ) {
+ push @$stack, namespace::clean::_ScopeGuard->arm(shift);
+ }
+ else {
+ tie( %^H, 'Tie::ExtraHash', namespace::clean::_ScopeGuard->arm(shift) );
+ }
+ }
+
+ 1;
+
+PP
+
+ }
+}
=head1 SYNOPSIS
=head1 DESCRIPTION
+=head2 Keeping packages clean
+
When you define a function, or import one, into a Perl package, it will
naturally also be available as a method. This does not per se cause
problems, but it can complicate subclassing and, for example, plugin
-classes that are included via multiple inheritance by loading them as
+classes that are included via multiple inheritance by loading them as
base classes.
The C<namespace::clean> pragma will remove all previously declared or
collecting functions for the next C<use namespace::clean;> specification.
You can use the C<-except> flag to tell C<namespace::clean> that you
-don't want it to remove a certain function. A common use would be a
-module exporting an C<import> method along with some functions:
+don't want it to remove a certain function or method. A common use would
+be a module exporting an C<import> method along with some functions:
use ModuleExportingImport;
use namespace::clean -except => [qw( import )];
+If you just want to C<-except> a single sub, you can pass it directly.
+For more than one value you have to use an array reference.
+
+=head2 Explicitly removing functions when your scope is compiled
+
+It is also possible to explicitly tell C<namespace::clean> what packages
+to remove when the surrounding scope has finished compiling. Here is an
+example:
+
+ package Foo;
+ use strict;
+
+ # blessed NOT available
+
+ sub my_class {
+ use Scalar::Util qw( blessed );
+ use namespace::clean qw( blessed );
+
+ # blessed available
+ return blessed shift;
+ }
+
+ # blessed NOT available
+
+=head2 Moose
+
+When using C<namespace::clean> together with L<Moose> you want to keep
+the installed C<meta> method. So your classes should look like:
+
+ package Foo;
+ use Moose;
+ use namespace::clean -except => 'meta';
+ ...
+
+Same goes for L<Moose::Role>.
+
+=head2 Cleaning other packages
+
+You can tell C<namespace::clean> that you want to clean up another package
+instead of the one importing. To do this you have to pass in the C<-cleanee>
+option like this:
+
+ package My::MooseX::namespace::clean;
+ use strict;
+
+ use namespace::clean (); # no cleanup, just load
+
+ sub import {
+ namespace::clean->import(
+ -cleanee => scalar(caller),
+ -except => 'meta',
+ );
+ }
+
+If you don't care about C<namespace::clean>s discover-and-C<-except> logic, and
+just want to remove subroutines, try L</clean_subroutines>.
+
=head1 METHODS
-You shouldn't need to call any of these. Just C<use> the package at the
-appropriate place.
+=head2 clean_subroutines
-=cut
+This exposes the actual subroutine-removal logic.
-=head2 import
+ namespace::clean->clean_subroutines($cleanee, qw( subA subB ));
-Makes a snapshot of the current defined functions and registers a
-L<Filter::EOF> cleanup routine to remove those symbols at the end
-of the compile-time.
+will remove C<subA> and C<subB> from C<$cleanee>. Note that this will remove the
+subroutines B<immediately> and not wait for scope end. If you want to have this
+effect at a specific time (e.g. C<namespace::clean> acts on scope compile end)
+it is your responsibility to make sure it runs at that time.
=cut
-sub import {
- my ($pragma, %args) = @_;
+my $sub_utils_loaded;
+my $DebuggerRename = sub {
+ my ($f, $sub, $cleanee_stash, $deleted_stash) = @_;
+
+ if (! defined $sub_utils_loaded ) {
+ $sub_utils_loaded = do {
+ my $sn_ver = 0.04;
+ eval { require Sub::Name; Sub::Name->VERSION($sn_ver) }
+ or die "Sub::Name $sn_ver required when running under -d or equivalent: $@";
+
+ my $si_ver = 0.04;
+ eval { require Sub::Identify; Sub::Identify->VERSION($si_ver) }
+ or die "Sub::Identify $si_ver required when running under -d or equivalent: $@";
+
+ 1;
+ } ? 1 : 0;
+ }
+
+ if ( Sub::Identify::sub_fullname($sub) eq ($cleanee_stash->name . "::$f") ) {
+ my $new_fq = $deleted_stash->name . "::$f";
+ Sub::Name::subname($new_fq, $sub);
+ $deleted_stash->add_symbol("&$f", $sub);
+ }
+};
+
+my $RemoveSubs = sub {
+ my $cleanee = shift;
+ my $store = shift;
+ my $cleanee_stash = Package::Stash->new($cleanee);
+ my $deleted_stash;
+
+ SYMBOL:
+ for my $f (@_) {
+
+ # ignore already removed symbols
+ next SYMBOL if $store->{exclude}{ $f };
+
+ my $sub = $cleanee_stash->get_symbol("&$f")
+ or next SYMBOL;
+
+ if ($^P and ref(\$cleanee_stash->namespace->{$f}) eq 'GLOB') {
+ # convince the Perl debugger to work
+ # it assumes that sub_fullname($sub) can always be used to find the CV again
+ # since we are deleting the glob where the subroutine was originally
+ # defined, that assumption no longer holds, so we need to move it
+ # elsewhere and point the CV's name to the new glob.
+ $DebuggerRename->(
+ $f,
+ $sub,
+ $cleanee_stash,
+ $deleted_stash ||= Package::Stash->new("namespace::clean::deleted::$cleanee"),
+ );
+ }
+
+ my @symbols = map {
+ my $name = $_ . $f;
+ my $def = $cleanee_stash->get_symbol($name);
+ defined($def) ? [$name, $def] : ()
+ } '$', '@', '%', '';
+
+ $cleanee_stash->remove_glob($f);
+
+ $cleanee_stash->add_symbol(@$_) for @symbols;
+ }
+};
- # calling class, all current functions and our storage
- my $cleanee = caller;
- my $functions = $pragma->get_functions($cleanee);
- my $store = $pragma->get_class_store($cleanee);
+sub clean_subroutines {
+ my ($nc, $cleanee, @subs) = @_;
+ $RemoveSubs->($cleanee, {}, @subs);
+}
- my %except = map {( $_ => 1 )} @{ $args{ -except } || [] };
+=head2 import
- # register symbols for removal, if they have a CODE entry
- for my $f (keys %$functions) {
- next if $except{ $f };
- next unless $functions->{ $f }
- and *{ $functions->{ $f } }{CODE};
- $store->{remove}{ $f } = 1;
- }
+Makes a snapshot of the current defined functions and installs a
+L<B::Hooks::EndOfScope> hook in the current scope to invoke the cleanups.
+
+=cut
- # register EOF handler on first call to import
- unless ($store->{handler_is_installed}) {
- Filter::EOF->on_eof_call(sub {
- SYMBOL:
- for my $f (keys %{ $store->{remove} }) {
-
- # ignore already removed symbols
- next SYMBOL if $store->{exclude}{ $f };
- no strict 'refs';
-
- # keep original value to restore non-code slots
- local *__tmp = *{ ${ "${cleanee}::" }{ $f } };
- delete ${ "${cleanee}::" }{ $f };
-
- SLOT:
- # restore non-code slots to symbol
- for my $t (qw( SCALAR ARRAY HASH IO FORMAT )) {
- next SLOT unless defined *__tmp{ $t };
- *{ "${cleanee}::$f" } = *__tmp{ $t };
- }
- }
- });
- $store->{handler_is_installed} = 1;
+sub import {
+ my ($pragma, @args) = @_;
+
+ my (%args, $is_explicit);
+
+ ARG:
+ while (@args) {
+
+ if ($args[0] =~ /^\-/) {
+ my $key = shift @args;
+ my $value = shift @args;
+ $args{ $key } = $value;
+ }
+ else {
+ $is_explicit++;
+ last ARG;
+ }
}
- return 1;
+ my $cleanee = exists $args{ -cleanee } ? $args{ -cleanee } : scalar caller;
+ if ($is_explicit) {
+ on_scope_end {
+ $RemoveSubs->($cleanee, {}, @args);
+ };
+ }
+ else {
+
+ # calling class, all current functions and our storage
+ my $functions = $pragma->get_functions($cleanee);
+ my $store = $pragma->get_class_store($cleanee);
+ my $stash = Package::Stash->new($cleanee);
+
+ # except parameter can be array ref or single value
+ my %except = map {( $_ => 1 )} (
+ $args{ -except }
+ ? ( ref $args{ -except } eq 'ARRAY' ? @{ $args{ -except } } : $args{ -except } )
+ : ()
+ );
+
+ # register symbols for removal, if they have a CODE entry
+ for my $f (keys %$functions) {
+ next if $except{ $f };
+ next unless $stash->has_symbol("&$f");
+ $store->{remove}{ $f } = 1;
+ }
+
+ # register EOF handler on first call to import
+ unless ($store->{handler_is_installed}) {
+ on_scope_end {
+ $RemoveSubs->($cleanee, $store, keys %{ $store->{remove} });
+ };
+ $store->{handler_is_installed} = 1;
+ }
+
+ return 1;
+ }
}
=head2 unimport
=cut
sub unimport {
- my ($pragma) = @_;
+ my ($pragma, %args) = @_;
# the calling class, the current functions and our storage
- my $cleanee = caller;
+ my $cleanee = exists $args{ -cleanee } ? $args{ -cleanee } : scalar caller;
my $functions = $pragma->get_functions($cleanee);
my $store = $pragma->get_class_store($cleanee);
=head2 get_class_store
-This returns a reference to a hash in a passed package containing
+This returns a reference to a hash in a passed package containing
information about function names included and excluded from removal.
=cut
sub get_class_store {
my ($pragma, $class) = @_;
- no strict 'refs';
- return \%{ "${class}::${STORAGE_VAR}" };
+ my $stash = Package::Stash->new($class);
+ my $var = "%$STORAGE_VAR";
+ $stash->add_symbol($var, {})
+ unless $stash->has_symbol($var);
+ return $stash->get_symbol($var);
}
=head2 get_functions
sub get_functions {
my ($pragma, $class) = @_;
+ my $stash = Package::Stash->new($class);
return {
- map { @$_ } # key => value
- grep { *{ $_->[1] }{CODE} } # only functions
- map { [$_, qualify_to_ref( $_, $class )] } # get globref
- grep { $_ !~ /::$/ } # no packages
- do { no strict 'refs'; keys %{ "${class}::" } } # symbol entries
+ map { $_ => $stash->get_symbol("&$_") }
+ $stash->list_all_symbols('CODE')
};
}
=head1 IMPLEMENTATION DETAILS
-This module works through the effect that a
+This module works through the effect that a
delete $SomePackage::{foo};
will remove the C<foo> symbol from C<$SomePackage> for run time lookups
(e.g., method calls) but will leave the entry alive to be called by
-already resolved names in the package itself.
+already resolved names in the package itself. C<namespace::clean> will
+restore and therefor in effect keep all glob slots that aren't C<CODE>.
A test file has been added to the perl core to ensure that this behaviour
will be stable in future releases.
Just for completeness sake, if you want to remove the symbol completely,
use C<undef> instead.
+=head1 CAVEATS
+
+This module is fully functional in a pure-perl environment, where
+L<Variable::Magic>, a L<B::Hooks::EndOfScope> dependency, may not be
+available. However in this case this module falls back to a
+L<tie()|perlfunc/tie> of L<%^H|perlvar/%^H> which may or may not interfere
+with some crack you may be doing independently of namespace::clean.
+
=head1 SEE ALSO
-L<Filter::EOF>
+L<B::Hooks::EndOfScope>
+
+=head1 THANKS
+
+Many thanks to Matt S Trout for the inspiration on the whole idea.
+
+=head1 AUTHORS
+
+=over
+
+=item *
+
+Robert 'phaylon' Sedlacek <rs@474.at>
+
+=item *
+
+Florian Ragwitz <rafl@debian.org>
+
+=item *
+
+Jesse Luehrs <doy@tozt.net>
+
+=item *
+
+Peter Rabbitson <ribasushi@cpan.org>
-=head1 AUTHOR AND COPYRIGHT
+=back
-Robert 'phaylon' Sedlacek C<E<lt>rs@474.atE<gt>>, with many thanks to
-Matt S Trout for the inspiration on the whole idea.
+=head1 COPYRIGHT AND LICENSE
-=head1 LICENSE
+This software is copyright (c) 2011 by Robert 'phaylon' Sedlacek.
-This program is free software; you can redistribute it and/or modify
-it under the same terms as perl itself.
+This is free software; you can redistribute it and/or modify it under the same terms as the Perl 5 programming language system itself.
=cut
-1;
+no warnings;
+'Danger! Laws of Thermodynamics may not apply.'
projects / p5sagit/namespace-clean.git / blobdiff